oru.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Özdemir, Nermin
Alternative names
Publications (10 of 29) Show all publications
Larsson, T., Kjellander, J. & Överstam, H. (2013). “Aerosoltrap” a new device for inertial dust separation: CFD simulations with experimental validation. Particulate Science and Technology, 31(3), 221-225
Open this publication in new window or tab >>“Aerosoltrap” a new device for inertial dust separation: CFD simulations with experimental validation
2013 (English)In: Particulate Science and Technology, ISSN 0272-6351, E-ISSN 1548-0046, Vol. 31, no 3, p. 221-225Article in journal (Refereed) Published
Abstract [en]

Inertial separation of dust from air/gas streams using settling- or baffle chambers is simple and cost effective. In order to increase the effectiveness of a single chamber AerosolTrap has been developed. This new device uses 4 chambers in series, stacked on top of each other. The aim of the present study is to examine the performance of AerosolTrap and investigate if CFD simulations can be used as a tool to optimize its geometry. Simulations and validating laboratory experiments have been performed using different flows and different mix of particles. The paper describes the methodology used and presents results that show that CFD simulations predict the general characteristics of the AerosolTrap well but underestimates the separation coefficient slightly.

Place, publisher, year, edition, pages
Taylor & Francis, 2013
Keywords
Aerosoltrap, CFD, computational fluid dynamics, inertial separation, particle trap
National Category
Engineering and Technology
Research subject
Mechanical Engineering; Building Technology
Identifiers
urn:nbn:se:oru:diva-25905 (URN)10.1080/02726351.2012.715612 (DOI)000317822100003 ()2-s2.0-84876391202 (Scopus ID)
Available from: 2012-09-19 Created: 2012-09-19 Last updated: 2017-12-07Bibliographically approved
Överstam, H., Johansson, H. & Jarl, M. (2011). Temperatures at wire-drawing: simulations and verification efforts. In: Hutnik: vol 78. Paper presented at IV International Conference on Drawing, Zakopane, 3-5 Mars 2011 (pp. 98-100).
Open this publication in new window or tab >>Temperatures at wire-drawing: simulations and verification efforts
2011 (English)In: Hutnik: vol 78, 2011, p. 98-100Conference paper, Published paper (Other academic)
Abstract [en]

Temperatures are very important in the wire drawing process. They are hard to measure direct, but a combination of simulations and measurements can give valuable information

Keywords
Temperature, simulation, drawing process
National Category
Mechanical Engineering
Research subject
Mechanical Engineering
Identifiers
urn:nbn:se:oru:diva-24299 (URN)
Conference
IV International Conference on Drawing, Zakopane, 3-5 Mars 2011
Projects
Teknik för högre draghastighet
Available from: 2012-08-07 Created: 2012-08-07 Last updated: 2017-10-17Bibliographically approved
Överstam, H. & Lundberg, S.-E. (2008). A new approach to roll force and torque modelling in wire rod and bar mills. Der Kalibreur, 69, 61-72
Open this publication in new window or tab >>A new approach to roll force and torque modelling in wire rod and bar mills
2008 (English)In: Der Kalibreur, ISSN 0022-796X, Vol. 69, p. 61-72Article in journal (Refereed) Published
National Category
Engineering and Technology Metallurgy and Metallic Materials
Research subject
Mechanical Engineering
Identifiers
urn:nbn:se:oru:diva-8415 (URN)
Available from: 2009-10-30 Created: 2009-10-30 Last updated: 2017-10-18Bibliographically approved
Jarl, M. & Överstam, H. (2008). Simulation of temperatures in the wiredrawing process. Wire Journal International, 41(2), 150-155
Open this publication in new window or tab >>Simulation of temperatures in the wiredrawing process
2008 (English)In: Wire Journal International, ISSN 0277-4275, Vol. 41, no 2, p. 150-155Article in journal (Refereed) Published
Place, publisher, year, edition, pages
Guilford, Conn.: Wire journal, 2008
National Category
Metallurgy and Metallic Materials Engineering and Technology Chemical Engineering
Research subject
maskinteknik
Identifiers
urn:nbn:se:oru:diva-8414 (URN)
Available from: 2009-10-30 Created: 2009-10-30 Last updated: 2017-10-18Bibliographically approved
Överstam, H. & Lundberg, S.-E. (2007). A new approach to roll force and torque modelling in wire rod and bar mills. Paper presented at AIKW, 77.
Open this publication in new window or tab >>A new approach to roll force and torque modelling in wire rod and bar mills
2007 (English)Conference paper, Oral presentation only (Other academic)
National Category
Engineering and Technology
Research subject
Mechanical Engineering
Identifiers
urn:nbn:se:oru:diva-4523 (URN)
Conference
AIKW, 77
Available from: 2008-03-26 Created: 2008-03-26 Last updated: 2017-10-18Bibliographically approved
Jarl, M. & Överstam, H. (2007). FEM vid tråddragning: resultat av dragförsök med SKF803. Örebro: Örebro universitet
Open this publication in new window or tab >>FEM vid tråddragning: resultat av dragförsök med SKF803
2007 (English)Report (Other academic)
Place, publisher, year, edition, pages
Örebro: Örebro universitet, 2007
Series
Studies from the department of technology at Örebro University, ISSN 1404-7225 ; 28
National Category
Mechanical Engineering
Research subject
Mechanical Engineering
Identifiers
urn:nbn:se:oru:diva-4528 (URN)
Available from: 2008-03-26 Created: 2008-03-26 Last updated: 2017-10-18Bibliographically approved
Lundberg, S.-E. & Överstam, H. (2007). Modelling of stress state, centre consolidation and roll force in billet rolling. Steel Research International, 78(6), 492-501
Open this publication in new window or tab >>Modelling of stress state, centre consolidation and roll force in billet rolling
2007 (English)In: Steel Research International, ISSN 1611-3683, Vol. 78, no 6, p. 492-501Article in journal (Refereed) Published
Abstract [en]

Roll pressure models have been derived from theoretical studies, FEM simulations and experimental investigations. A model developed from slip line field theory has been shown to fit well to the experimental results. The finite element simulations overestimated the pressure function. This is a common problem in hot rolling experiments, since the problem of measuring the correct rolling temperature makes the estimation of the yield strength very difficult. The difference between the FE calculations and the experimental measurements is a measure for the error in the experimental temperature measurements rather than for the accuracy of the finite element method. Traditional modelling has not been an appropriate tool to evaluate the material flow in the centre of the billet. In spite of the fact that the entire stress state can be modelled by slip line field theory, the slip lines which determine the stress state in the centre coincide for actual geometries only in one single point. Thus the strain increments are known only in that single point. Since a material element passes that point instantaneously, it is not possible to find any finite strains in the centre by integrating any incremental function. By FEM, strain modelling is simple and the possibility to consolidate a porous bloom or ingot core can be determined. FE modelling requires an entirely new approach to the modelling problem. It is not reasonable to use FEM to evaluate only the temperature distribution for the use in roll force models from the previous century. Instead, a fully thermomechanically coupled FE model is suggested. However, the calculation time is still far too long to be used for on-line control purposes. For this application hybrid modelling can be a solution, where off-line FE models are combined with empirical modelling, and simplified models can be used for the process control.

Place, publisher, year, edition, pages
Düsseldorf: Stahleisen, 2007
Keywords
billets, finite element analysis, hot rolling, slip, steel manufacture, stress effects, yield strength
National Category
Engineering and Technology
Research subject
maskinteknik
Identifiers
urn:nbn:se:oru:diva-4510 (URN)DH90-2007-001 (PubMedID)
Available from: 2008-03-26 Created: 2008-03-26 Last updated: 2017-10-18Bibliographically approved
Jarl, M. & Överstam, H. (2007). Simulation of temperatures in the wiredrawing process. Paper presented at International Wire and Cable conference, Bologna 2007.
Open this publication in new window or tab >>Simulation of temperatures in the wiredrawing process
2007 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

Hydrodynamic theory predicts higher pressure at higher drawing speed, but the opposite is true. The temperature in the area of wire and die interface influences lubricant properties, including viscosity. In this paper, the wiredrawing process was studied by means of coupled thermo-mechanical simulations using the Finite Element Method. The temperatures in the die, the wire, and the interface were evaluated, for different parameters such as wire steel grade, drawing speed, and die cooling conditions. This paper discusses their influence on lubrication.

Keywords
wiredrawing, simulation, temperature, lubricant
National Category
Mechanical Engineering
Research subject
Mechanical Engineering
Identifiers
urn:nbn:se:oru:diva-4161 (URN)
Conference
International Wire and Cable conference, Bologna 2007
Available from: 2007-11-16 Created: 2007-11-16 Last updated: 2017-10-18Bibliographically approved
Filipovic, M., Ericsson, C. & Överstam, H. (2006). Behaviour of surface defects in wire rod rolling. Steel Research International, 77(6), 439-444
Open this publication in new window or tab >>Behaviour of surface defects in wire rod rolling
2006 (English)In: Steel Research International, ISSN 1611-3683, E-ISSN 1869-344X, Vol. 77, no 6, p. 439-444Article in journal (Refereed) Published
Abstract [en]

Defects are often present in rolled products, such as wire rod. The market demand for wire rod without any defects has increased. In the final wire rod products, defects originating from steel making, casting, pre-rolling of billets and during wire rod rolling can appear. In this work, artificial V-shaped longitudinal surface cracks have been analysed experimentally and by means of FEM. The results indicate that the experiments and FEM calculations show the same tendency except in two cases, where instability due to fairly "round" false round bars disturbed the experiment. FE studies in combination with practical experiments are necessary in order to understand the behaviour of the material flows in the groove and to explain whether the crack will open up as a V-shape or if it will be closed as an I-shape.

Keywords
Rolling, Steelmaking, Cracks, Surface properties, Finite element method, Artificial surface cracks, Wire rod, Working range, Roll pass design, FE-analysis
National Category
Mechanical Engineering
Research subject
Mechanical Engineering
Identifiers
urn:nbn:se:oru:diva-4429 (URN)
Available from: 2007-07-12 Created: 2007-07-12 Last updated: 2017-12-14Bibliographically approved
Överstam, H. (2006). Evaluation of the improvement of rolling analysis by means of modern technology. Paper presented at Instituto Argentino de Siderurgia 16th Rolling Conference; Buenos Aires.
Open this publication in new window or tab >>Evaluation of the improvement of rolling analysis by means of modern technology
2006 (English)Conference paper, Published paper (Other academic)
Abstract [en]

Modern wire rod rolling is characterised by high rolling speed and requirements on well-defined mechanical properties as well as close tolerances. Traditional methods for analyses of this kind of processes, such as the slip line field theory and the upper bound analysis, have proven not to be sufficient. Different methods for rolling analysis have been evaluated. Several FE approaches were compared to classical methods such as the upper bound and the slip line theory and the results was validated by practical experiments. The finite element method has proven to be a powerful tool in order understand the metal working process, it also gives the possibility to study phenomena not yet clarified.

National Category
Mechanical Engineering
Research subject
Mechanical Engineering
Identifiers
urn:nbn:se:oru:diva-4070 (URN)
Conference
Instituto Argentino de Siderurgia 16th Rolling Conference; Buenos Aires
Available from: 2007-06-21 Created: 2007-06-21 Last updated: 2017-10-18Bibliographically approved
Organisations

Search in DiVA

Show all publications